<?xml version="1.0"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema"
        xmlns:gml="http://www.opengis.net/gml"
        targetNamespace="http://www.opengis.net/gml"
        version="3.1.1" elementFormDefault="qualified">

  <include schemaLocation="measures.xsd"/>

  <element name="_Geometry" type="gml:AbstractGeometryType"
           abstract="true" substitutionGroup="gml:_GML"/>
  <complexType name="GeometryPropertyType">
    <sequence>
      <element ref="gml:_Geometry"/>
    </sequence>
  </complexType>

  <complexType name="GeometryArrayPropertyType">
    <sequence>
      <element ref="gml:_Geometry"
               minOccurs="0" maxOccurs="unbounded"/>
    </sequence>
  </complexType>

  <complexType name="AbstractGeometryType" abstract="true">
    <complexContent>
      <extension base="gml:AbstractGMLType">
        <attribute name="gid" type="string" use="optional">
        </attribute>
        <attributeGroup ref="gml:SRSReferenceGroup"/>
      </extension>
    </complexContent>
  </complexType>

  <attributeGroup name="SRSReferenceGroup">
    <attribute name="srsName" type="anyURI" use="optional"/>
    <attribute name="srsDimension" type="positiveInteger"
               use="optional"/>
    <attributeGroup ref="gml:SRSInformationGroup"/>
  </attributeGroup>

  <attributeGroup name="SRSInformationGroup">
    <attribute name="axisLabels" type="gml:NCNameList"
               use="optional"/>
    <attribute name="uomLabels" type="gml:NCNameList"
               use="optional">
    </attribute>
  </attributeGroup>

  <element name="_GeometricPrimitive"
           type="gml:AbstractGeometricPrimitiveType" abstract="true"
           substitutionGroup="gml:_Geometry"/>
  <complexType name="AbstractGeometricPrimitiveType" abstract="true">
    <complexContent>
      <extension base="gml:AbstractGeometryType"/>
    </complexContent>
  </complexType>

  <element name="Point" type="gml:PointType"
           substitutionGroup="gml:_GeometricPrimitive"/>
  <complexType name="PointType">
    <complexContent>
      <extension base="gml:AbstractGeometricPrimitiveType">
        <sequence>
          <element ref="gml:pos"/>
        </sequence>
      </extension>
    </complexContent>
  </complexType>

  <element name="pointProperty" type="gml:PointPropertyType"/>
  <complexType name="PointPropertyType">
    <sequence>
      <element ref="gml:Point"/>
    </sequence>
  </complexType>

  <element name="_Curve" type="gml:AbstractCurveType" abstract="true"
           substitutionGroup="gml:_GeometricPrimitive"/>
  <complexType name="AbstractCurveType" abstract="true">
    <complexContent>
      <extension base="gml:AbstractGeometricPrimitiveType"/>
    </complexContent>
  </complexType>

  <element name="curveProperty" type="gml:CurvePropertyType"/>
  <complexType name="CurvePropertyType">
    <sequence>
      <element ref="gml:_Curve"/>
    </sequence>
  </complexType>

  <element name="LineString" type="gml:LineStringType"
           substitutionGroup="gml:_Curve"/>
  <complexType name="LineStringType">
    <complexContent>
      <extension base="gml:AbstractCurveType">
        <sequence>
          <choice>
            <choice minOccurs="2" maxOccurs="unbounded">
              <element ref="gml:pos"/>
              <element ref="gml:pointProperty"/>
            </choice>
            <element ref="gml:posList"/>
          </choice>
        </sequence>
      </extension>
    </complexContent>
  </complexType>

  <element name="pos" type="gml:DirectPositionType"/>
  <complexType name="DirectPositionType">
    <simpleContent>
      <extension base="gml:doubleList"/>
    </simpleContent>
  </complexType>

  <element name="posList" type="gml:DirectPositionListType"/>
  <complexType name="DirectPositionListType">
    <simpleContent>
      <extension base="gml:doubleList">
        <attribute name="count" type="positiveInteger"
                   use="optional"/>
      </extension>
    </simpleContent>
  </complexType>

  <element name="Envelope" type="gml:EnvelopeType"/>

  <complexType name="EnvelopeType">
    <choice>
      <sequence>
        <element name="lowerCorner" type="gml:DirectPositionType"/>
        <element name="upperCorner" type="gml:DirectPositionType"/>
      </sequence>
      <element ref="gml:pos" minOccurs="2" maxOccurs="2"/>
    </choice>
    <attributeGroup ref="gml:SRSReferenceGroup"/>
  </complexType>

</schema>
